/** This is a common shader part, not a standalone GLSL file */
uniform float eqRC[4];

/** @note in EmbedEnv: any function must not add extra ';' at end of the function! */
float getLineXR(float z) {
	float C0 = eqRC[0];
	float C1 = eqRC[1];
	float C2 = eqRC[2];
	float C3 = eqRC[3];
	float x = - (C0 + C1 * (-z) + C2 * pow(-z, 2.0) + C3 * pow(-z, 3.0));
	return x;
}